A power management for probabilistic clock synchronization in wireless sensor networks

Low power consuming is one of the most critical characteristics for wireless sensor networks (WSNs). At the same time, clock synchronizations are necessary processes in normal WSNs works. The synchronization processes consume a lot of energy because of frequent communications between sensor nodes. The main energy consumers of sensor nodes are microcontrollers, radio transceivers, memory, sensors and actuators. Usually, researchers reduce numbers of communications by switching different operation modes of these components to reduce the energy consumption. However, the precision of synchronization will fall during idle modes because of clock drift. The goal of achieving both synchronization algorithm accuracy and energy efficiency in the same time is difficult to reach or is impractical in reality. Therefore, trading-off between computation quality and energy consumption must be made for a real application synchronization algorithms running on wireless sensors. Then, a model of probabilistic clock synchronization for sensor nodes is built and a trading-off between synchronization precision and energy consumption is supplied to illustrate such trade-off policies. The results of the analysis show that the energy consumption can be reduced by sleep mode without drop the synchronization precision too much.